These sensors can only estimate based on what passes through them. So is it a good enough approximation for the whole room let alone the whole house? I get it t

These sensors can only estimate based on what passes through them. So is it a good enough approximation for the whole room let alone the whole house? I get it that the very presence of some particles at some density will tell a story. Since we know where we are placing that device we have to extrapolate the numbers and get an overall sense of pollution in the house. Can folks that use something like this chime in with experience and how effective or useful this is?